Description

Radiofrequency and microwave radiation are both
forms of energy called electromagnetic radiation. Sunshine contains three
other forms of electromagnetic radiation: ultraviolet rays, infrared
(heat) waves, and visible light waves.

These forms of energy are transmitted by waves. The
distance between wave peaks is the "wavelength." The number of
wave peaks passing a given point in one second is the
"frequency."

Radiofrequency or radiowaves have a
range of frequencies and wavelengths. Very High Frequency (VHF) radiowaves
are used for TV and FM radio. Medium Frequency (MF) radiowaves are used
for AM radio. Radiofrequency is used in heat sealers and glue driers.

Microwaves are actually just
radiowaves of higher frequencies. Microwaves are used for radar and
satellite communications, for telephone and TV transmissions, for
microwave ovens, and for diathermy in medical clinics.

Electromagnetic radiation can
interact with objects (or people) in three different ways. The energy
waves can pass through an object without being changed, like light through
a window. It can be reflected, like light off a mirror, or it can be
absorbed and cause the object to heat up, like a sidewalk in the sun.

The health hazards of
electromagnetic radiation are related only to the absorption of energy.
The effects of absorbed energy depend on many different factors such as
its wavelength and frequency, its intensity and duration. Different
materials also absorb energy differently.

When microwaves or radiowaves are
absorbed by body tissues, localized or spot heating can occur. The
increased temperature can damage tissues, especially those with poor
temperature control such as the lens of the eye.

Cataracts, clouding of the lens of
the eye, may occur at the very high energy levels encountered close to
radiating radar antennas. Heat damage to tissues is caused by high levels
of exposure for short periods of time.

The health effects of low levels of exposure to
radiowaves or microwaves for long periods of time are much harder to find
and to prove. Some scientific studies show health effects from long-term,
lowlevel exposure, other studies do not.

The following list includes health effects which
some researchers suspect may be related to excessive radiofrequency/microwave
exposure:

Psychological changes, e.g., insomnia,
irritability, mood swings,

depression

Headaches

Nervous system abnormalities

Hormonal changes

Miscarriages and birth defects

Male Infertility

Altered immunity

Leukemia

Of course, many of these health effects are
relatively common, and most people having these problems have NOT had
excessive exposure to radiofrequency/microwave radiation.

Employers who have people working
around devices which produce radiofrequency/microwave radiation need to be
sure that those devices are properly shielded to prevent leakage of
radiation. Safety information regarding proper use and shielding of those
devices can usually be obtained from owner/operators manuals,
manufacturers, and the Alaska Department of Labor Occupational Safety and
Health Section.

Radiofrequency sealers and heaters
have been among the major sources of employee exposure to radiofrequency/microwave
radiation. When these machines are used, employees should use mechanical
or electrical devices that allow them to stay as far away form the source
of radiation as possible. Whenever possible, these sealers should be
turned off when not being used. Maintenance and adjustment of this type of
equipment should be performed only by trained technicians and only when
the machines are turned off.

Warnings should be posted to keep
everyone away from the source of radiation except for those workers who
are absolutely essential to performing the job.

People who are regularly exposed to
significant levels of radiofrequency/microwave radiation should have
preemployment and annual physical exams. The doctors should pay careful
attention to the eyes to look for cataracts, to the nervous system for any
abnormalities to the blood, to detect any early evidence of leukemia, and
to the reproductive system to detect any abnormalities. Information
concerning the frequency and intensity of the radiation exposures and
duration of exposures should be provided to the physician.

In work areas where there is known
or suspected to be significant amounts of radiofrequency/microwave
radiation present, specialists should measure the amounts of radiation
present. If excessive radiofrequency/microwave radiation is detected,
modifications in the workplace should be made to reduce radiation exposure
of workers. Afterwards, additional measurements should be made to
determine if the radiation exposure has been reduced.

The State of Alaska's permissible
exposure limit is specified in Article I of Subchapter 4, Occupational
Health and Environmental Control Code [04.0106(a)], Alaska Occupational
Safety and Health Standards. For normal environmental conditions and for
incident electromagnetic energy of frequencies from 10 MHz to 100 GHz, the
radiation protection guide is 10 mW/cm (milliwatts per square centimeter)
as averaged over any possible six-minute period.

Further information can be obtained from the Alaska
Department of Labor, Occupational Safety and Health Section.